Additional Balance Sheet Detail and Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Information [Abstract]

Schedule of Accrued Liabilities [Table Text Block]

Accrued liabilities and other consist of the following:

	December 31, 2017		December 31, 2016
Accrued salaries and wages	$	26,559	$	20,895
Income and mining taxes	25,788		3,721
Silvertip contingent consideration	24,393		—
Accrued operating costs	12,323		3,199
Taxes other than income and mining	4,354		2,738
Accrued interest payable	1,513		5,892
Accrued liabilities and other	$	94,930	$	36,445

Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]

The following table presents non-cash financing and investing activities and other cash flow information:

	Year ended December 31,
Non-cash financing and investing activities:	2017		2016		2015
Capital lease obligations	$	34,604	$	32,243	$	4,123
Non-cash extinguishment of senior notes	—		10,616		53,373
Non-cash acquisitions and related deferred taxes	131,833		—		297,821
Other cash flow information:
Interest paid	$	21,943	$	41,919	$	41,442
Income taxes paid	13,000		17,181		1,937